Revert gradle properties changes

Author: mustard-mh

components/ide/jetbrains/backend-plugin/gradle-latest.properties

@@ -2,7 +2,7 @@
 # See https://plugins.jetbrains.com/docs/intellij/build-number-ranges.html
 # for insight into build numbers and IntelliJ Platform versions.
 # revert pluginSinceBuild if it's unnecessary
-pluginSinceBuild=243.21565
+pluginSinceBuild=243.15521
 pluginUntilBuild=243.*
 # Plugin Verifier integration -> https://github.com/JetBrains/gradle-intellij-plugin#plugin-verifier-dsl
 # See https://jb.gg/intellij-platform-builds-list for available build versions.